1. Field of the Invention
The present invention relates to a multiple lamp driving device capable of being applied to a multiple lamp system such as an LCD; and, more particularly, to a multiple lamp driving device comprising a balance transformer capable of balancing currents flowing through a plurality of lamps and reducing the number of balance transformers and the number of used elements to thereby remarkably reduce the entire area of a circuit by implementing a current balancing circuit including a plurality of balance transformers each of which includes a primary side, a first secondary side, and a second secondary side to thereby receive a high voltage from a voltage driving unit at the primary sides of the balance transformers, transmit the high voltage to the first secondary sides and the second secondary sides, and transmit driving power to the lamps connected to the secondary sides.
2. Description of the Related Art
Recently, various studies have been progressed in the field of inverter that is one of many elements constituting an LCD(Liquid Crystal Display) to reduce a manufacture cost. Approximately 16 to 24 CCFLs(Cold Cathode Fluorescent Lamps) are used to manufacture a backlight of an LCD TV and the same number of inverters are also required to drive it.
Meanwhile, if one inverter drives a plurality of lamps in parallel, it is expected to radically cut the cost. However, it is known that because as for a general CCFL, lamp resistance values differently change in ignition and in burning, it is difficult to drive the CCFLs in parallel.
It is known that if a current balancing transformer is used when driving them in parallel in order to overcome the above problem, it is possible to turn on multiple lamps and balance currents.
A method where one inverter can many lamps at the same time by using the current balancing transformer is referred to as a current balance method. As for the current balance method, there is a Jin balancing method, a Zaulas method, or an O2 micro method and a multiple lamp driving device using the Jin balancing method is described with reference to FIG. 1.
FIG. 1 is a construction view showing a conventional multiple lamp driving device and referring to FIG. 1, the conventional multiple lamp driving device includes an AC power source 10 for supplying driving power, a plurality of lamps 20(1)˜20(n) turned on by the driving power from the AC power source 10, and current balancing circuits 30(1)˜30(n) for uniformly balancing currents flowing through the lamps 20(1)˜20(n).
Herein, the current balancing circuits 30(1)˜30(n) include first to nth balance transformers individually corresponding to the lamps in order to uniformize the currents flowing through the lamps. A current balance principle of the current balancing circuit is known and therefore explanation thereof is omitted.
However, since the conventional multiple lamp driving device should use the balance transformers as many as the lamps, the entire area of the circuit are increased with increment of the number of the used elements, thereby complicating the circuit and increasing the manufacture cost.